Di-halogen substituted alpha-(p-hydroxyphenyl)-alpha-amino-acetic acid hydrohalides of the same, and processes for their production



Patented Jan. 31, 1939 DI-HALOGEN SUBSTITUTED oc-(P-HYDROX- YPHENYL)-oc-AMINO-ACETIC ACID HY- DRO-HALIDES OF THE. SAIWE, AND PROG- ESSES FOR, THEIR PRODUCTION Otto Dalmer and John Niemann, Darmstadt, Germany, assignors to Merck & 00., Inc., Rahway, N. J., a corporation of New Jersey No Drawing. Original application July 10, 1934,

Serial No. 734,510. Divided and this application September 18, 1935, Serial No. 101,410. In Germany August 23, 1933 9 Claims. (Cl. 260518) This is a division of application Serial No. 734,- 510, filed July 10, 1934, now Patent No. 2,085,009.

Our invention relates to antithyroidic compounds, and more particularly to compounds for use in counteracting abnormally increased basal metabolism.

Material increase in basal metabolism, a manifestation of Basedows disease, results in rapid loss of weight, which often proves fatal, if left and amino groups in ez-DOSitiOIl to each other).

It was not expected that such unphysiological' compositions would have an antithyrodicic effect, and still less to be expected that they would be more effective than the other known substances,

some of which occur naturally.

3, dibromoand 3, 5 di-iodo-u- (p-hydroxyphenyl) -a-amino-acetic acid are compounds thus far unknown, which decompose at 204 and 207,

untreated. Basedows disease is caused by hyperrespectively, when slowly heated, and split oif function of the thyroid gland, and its treatment halides. Their compositions correspond to the is based on prevention of increase in basal formulae: CsHqOaNBrz and CaHwOzNIz. metabolism. The new compounds were tested pharmaco- Previous to our invention, di-iodo-tyrosine and logically on rats whose basal metabolism had been dibromotyrosine were used in the treatment of increased by daily administrations of thyroxin, Basedows disease, but their antithyroidic effect 0.15 mg/kg. By simultaneous administration of was relatively low compared with the new coman antithyroidic preparation, the effect of thyroxpounds which constitute our invention. in can be more or less compensated, according It is, therefore, an object of our invention to to the effectiveness of the preparation. In the provide compounds which, when administered in following table, the increases in basal metabolism the proper manner, will tend to prevent increase are given, which were found on the 9th day of the in basal metabolism. experiment in the controls and test animals,

Some time ago, it was pointed out that di-iodotreated daily with 50 mg. and 100 mg; of the subtyrosine, which had thus far been regarded as stance (average values of at least three test anihaving hypermetabolic action similar to thyroxin, mals).

the hormone of the thyroid gland, was really Table hypo-metabolic when given in small doses. Dibromtyrosine acts in a similar manner. These Increasein basal two substances have, in the meantime, proved 'metablllism' beneficial in the treatment of Basedows disease. Controls Small quantities of di-iodo-tyrosine occur +2 naturally in the thyroid gland. Chemically, and 100 probably genetically, as Well, it is closely related to thyroxin and can, according to its physiological Pmem Percent ion, be re rded as an nta onist of t iifriit iyittg::::::::::::::::::::::::::::: ii in roXin. Since the dibromo compound of tyrosine q y yp e Y )a ohad also proved effective, indicating that the acp g g -h d y henyb-e-amino-acetic 2 +3 tion appears to be linked with the tyrosine molemid cule, other iodine and bromine derivatives of tyrosine were prepared. However, pharmaco- The superiority of the new compounds'over logical tests showed that the monobromotyrosine the old ones is quite aparent. and the bromo-iodo-tyrosine (the latter thus far The new group of compounds were obtained unknown) were without efiect upon artificially by treating a-(p-hydroxyphenyl)-a -amino-acetic increased basal metabolism. acid with such a quantity of halogenating agent It is, therefore, quite surprising that the iodo that two atoms thereof are introduced into the and bromo compounds respectively, of a-(p-hyphenyl radical. It was found that halogenation droxyphenyl) -e-arnino-acetic acid, prepared acmay easily be performed, and, therefore, the ordicording to the present invention, show an antinary methods described in the literature will serve thyroidic effect not only equal to, but considerthe general purpose.

ably exceeding that, of di-iodo-tyrosine. Nevertheless, it was found that especially pure It is notable that the primary substance for products can be obtained with smooth reaction, these new halogen compounds of oc-(D-hYdIOXY- if the halogenation is carried out in solutions phenyl) -e-amino-acetic acid does not occur natmade alkaline with sodium carbonate or bicarurally in the organism and presents an unphysibonate, or in solutions of corresponding alkalinity.

ological groupingin the molecule (phenyl radical Weak alkalinity can, of course, also be attained by adding alkali gradually during the reaction. t was found also that the hydrochlorides, as Well as hydrobromides of the new compounds, crystallize out of the acidulated reaction solution in a comparatively pure condition and are suitable for immediate further purification by ordinary means. Eatample'l;

5 grams of a-(p-hydroxyphenyl)-a-aminoacetic acid are dissolved in about 100 cc. diluted alkali solution and gradually 10 grams of iodine monochloride are added. The precipitation is completed with the addition of acetic acid. The yield is about '7 grams of crude di-iOdO-a-(D-hY- droxyphenyl)a-amino-acetic acid which can be purified by re-precipitation, for instance, with acetic acid from an ammoniacal solution of such crude acid, or by recrystallization, for instance, from diluted. alcohol or diluted acetic acid, or through conversion into the hydrochloride.

Ezcample 3 5 grams of m-(p-hydroxyphenyl)air-aminoacetic acid are dissolved in about 100 cc. alkali solution and 15.3 grams of powdered iodine added gradually while cooling. After standing for several hours, the solution is acidulated. The crude yield is about 8 grams. Purification was made as above.

Example 4 5 grams of a-(p-hydroxyphenyl)flat-aminoacetic acid are dissolved in about 100 cc. diluted hydrochloric acid, adding 10. grams of iodine monochloride in several portions. After prolonged standing, the precipitate is separated. The yield is about 5 grams. Purification was made as above.

Example 5 2.5 grams u-(p-hydroxyphenyl) -a-amino-acetic acid in 100 com. of 10% soda solution is shaken up with 7.6 grams of powdered iodine until solution has been effected, and then filtered after short treatment with animal charcoal, and the reaction liquid is then poured into 100 com. of 11% solution of hydriodic acid. The hydriodide of dl-iOdO-oz- (p-hydroxyphenyl) -a-amino-acetic acid is precipitated out. It melts under decomposition at 190194 C.

Example 6 8.4 grams of a(p-hydroxyphenyl) -lit-aminoacetic acid are suspended in. glacial acetic acid and a solution of 16 grams oi bromine in glacial acetic acid added. After heating for 1 hour, the solution is allowed to cool, whereby the hydrobromide will crystallize out. The yield is 13-15 grams. By recrystallization from water, the hydro-bromide is purified; from it, the free amino acid is obtained in fine needles by the addition of sodium acetate to its aqueous solution.

Obviously, the various steps of the process may be modified considerably with respect to the order and the number of steps and the specific materials used in the several methods, without departing from the spirit of the invention substantially as described and claimed, and it is understood that we do not desire to limit ourselves to the specific embodiments shown in the foregoing examples.

We claim as our invention:

1. A process for producing di-halcgen cc-(D- hydroxyphenyl)-a-amino-acetic acid hydrohalides comprising treating oc-(D-hYdIOXYPhGIIYl) -aamino-acetic acid with a halogenating agent and subsequently treating the reaction product with the desired acid.

2. A process for producing di-iodo-w-(p-hydroxyphenyl)-a-amino-acetic acid hydrochloride which comprises dissolving a-(p-hydroxyphenyl)-a-amino-acetic acid in 2 n-soda solution, agitating the mixture with iodine, decolorizing said mixture with charcoal, running said charcoal-treated mixture into hydrochloric acid, and permitting the hydrochloride to crystallize out.

3. A process for producing di-iOdO-a-(IJ-hY- droxyphenyl) -a-amino-acetic acid hydriodide which comprises shaking a-(phydroxyphenyl)- a-amino-acetic acid in soda solution with iodine, treating the mixture with charcoal, pouring said mixture into hydriodic acid, and permitting the hydriodide to precipitate out.

4. A process for producing dibromo-a-(p-hydroxyphenyl) -u-amino-acetic acid hydrobromide which comprises suspending a-(p-hydroxyphenyD-a-aminO-acetic acid in glacial acetic acid, adding a solution of bromine in glacial acetic acid, heating the mixture for a protracted period, cooling said mixture, and permitting the hydrobromide to crystallize out.

5. Di-iodo-u-(p-hydroxyphenyl) -a-aminoacetic acid hydrochloride occurring as a white powder of slightly bitter taste and melting at 205- 206 with decomposition.

6. Di-iodo-a-(p-hydroxyphenyl) -u-amino-acetic acid hydriodide, melting under decomposition at 190-194: C.

'7. Di bromo a (p hydroxyphenyl) a aminoacetic acid hydrobromide characterized in that the free acid may be obtained from it in fine needles by the addition of sodium acetate to its aqueous solution.

8. The process for producing hydrohalides of (ii-halogen substituted oc-(P-hYdIOXYphGnYl) -11- amino-acetic acid which comprises reacting upon a-(p-hydroxyphenyl) -a-amino-acetic acid with a halogenating agent in such quantity that two atoms thereof are introduced into the phenyl radical, and subsequently treating the reaction product with a hydrohalogen acid, to produce the corresponding hydrohalide of the di-halogenated oc-(D-hYdI'OXYPht-ZIIYI)-a-amllf10- acetic acid.

9. A di-halogen-a(p-hydroxyphenyl) -a-amino-acetic acid hydrohalide.

OTTO DALMER- JOHN NIEMANN. 

